Safety device for power-presses.



T. BUMANN. SAFETY DEVICE FOR POWER PRESSES.

APPLICATION FILED JUNE 5, 1913.

1,091,1 1 7. Patented Mar. 24,1914.

anuamto'o Ifi lama/ 7072 THEODORE BUMANN, or LITCHIFIELI), ILLINOIS.

SAFETY DEVICE FOR. POWEBFPRES SES.

Specification of Letters i'atent.

Patented Mar. 24, 1914.

Application filed June 5, 19-13. Serial No. 771,986. i I

To all whom it may concern Be'it known that I, THEODORE BUMANN, a citizen of the United States, residing at Litchfield, in the county of Montgomery and State of Illinois, have invented certain new and useful Improvements in Safety Devices for Power-Presses; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and usethe same.

This invention relates to safety devices for manually controlled power driven presses and other machines.

The object of the invention is to provlde a simply constructed and eflicient device which may be readily applied to any ma chine already constructed and which 'w1ll render it necessary for the operator to use both of his hands at points remote from the plunger or other power operated part of the machine to start the machine thus positively preventing injury to the hands of the operator.

Another object is to provide a device of this character which can be manufactured and applied to machines at small expense and which will not materially increase the labor of operating the machine or preventthe rapid operation thereof.

I This invention consists primarily in a safety appliance for hand fed power presses embodying therein a locking device for the treadle which operates the tripping mechanism of the machine .and means for preventing said locking device from being released until both hands of the operator are moved away from the-dies.

With these and other objects in view, the invention consists of certain novel features of construction, and the combination and arrangement of parts as will be more fully described and claimed. I

In the accompanying drawings: Figure 1 represents a perspective viewof a power press equipped with thls improved safety appliance, said appliance being shown in inoperative position; Fig. 2 is a front elevation of a portion of a press equipped with this improved safety device and with the parts in the same position as shoWn in Fig.

1; Fig. 3 isa side elevation thereof with the device in operative position; Fig. 4 1s a detail perspective view of the treadle lockinglever.

In the embodiment illustrated one form of stamping press A is shown of which there are numerous types but it is to be clearly understood that this improved safety deylce is equally applicable to all. In the parts here shown a indicates the frame which carries the bed for the die indicated at b, the plunger is indicated at 0, afly wheel; at and a trip actuating treadle 6, all of which parts are old and well known and consequently a detail description and illustration 'thereof are not deemed necessary.

.This improved safety device comprises a lever 1 shown in detail in Fig. 4, as hinged at its lower end to the floor within the base of the machine adjacent the treadle e and has a notch or step 2 formed near said lower end in position to engage the treadle e when ward movement. A coiled spring 3 connects this lever with the frame a and exerts its tension to draw said lever toward the treadle e to cause the step 2 thereof to normally engage said treadle and hold it against'actu ation. The upper end of this lever 1 has an operating handle 4 here shown in the form of .a laterally extending bent terminal projecting outward for convenience of the operator and this lever is slidably mounted on the frame a and-is guided in its movements and held by a strap 5 secured to the frame a at the front of the machine and spaced a suitable distance therefrom to permit the lever to move readily between it and the frame as shown clearly in Fig. 1. When this lever 1 is moved to its limit toward the left the step 2 thereof will be moved from under the treadle e and said treadle will be then ready for actuation or depression by the foot of the operator, the lever being held in this position by the hand of the operator,

against the tension of the spring 3 and when released the said spring will move it automatically toward the right of the machine into locking position for holding the treadle in raised position.

A guard plate 6 is h ingedly mounted at the front of the frame on the bed supporting the die I) and is adapted to be raised and lowered for a purpose now to be described. This guard when lowered extends laterally from" the bed of the machine in substan tially the same plane therewith and it capnot be so lowered until the lever l is moved to its extreme limit toward the right as the lever projects above the bed of the machine and prevents the lowering of said plate or guard until moved to its extreme limit toward the right. When said lever is in this position the plate may be lowered as shown in Fig. 3 and it will lock said lever against movement toward the left and thereby hold it securely inengagement with the treadle e, and thus prevent actuation of the treadle.

When it is desired to depress the treadle for actuating the plunger 0 the guard 6 must first be raised and the lever 1 moved toward the left to disengage the step 2 thereof from the treadle e and to accomplish this-it is necessary that both hands of the operator be used, one to raise the plate 6 and the other to move the lever l to the left thus insuring that both hands will be out of the way of the'plunger before the treadle e is depressed for throwing the plunger into operation. When raised this plate 6 also forms a guard extending be tween the operator and the dies of the machine and thus preventing accidental insertion of the operators hands between the dies and consequent injury thereto.

While I have described my invention with more or less minuteness as regards details and as being embodied in certain precise forms thereto unduly any more than is pointed out in the'claims. On the contrary, I contemplate all proper changes in form, construction and arrangement, the omission of immaterial elements and substitution of equivalents as circumstances may suggest or render expedient.

I claim as my invention:

1. The combination with a power press having a tripping treadle; of an upright swingin lever having means for engaging the trea le to support it in raised position, resilient means for holding said lever .normally in engagement with said treadle, and a pivotally mounted member swinging in a I do not desire to be limited.

plane at right angles to that in which the lever swings for locking said lever in engagement with said treadle when the treadle is in inoperative position.

2. The combination with a power press having a tripping treadle, of a lever having means for engaging the treadle to support it in raised position, resilient means for holding said lever normally in engagement with said treadle, and pivotally mounted means for locking said lever in engagement with said treadle when the treadle is in inoperative position.

- 3. The combination with a power press having a tripping treadle, of a lever fulcrumed adjacent said treadle and having means for supporting it normally in raised inoperative position, a hinged uard plate adapted to be lowered when said lever is in locking engagement with said treadle for holding the lever in this position, said lever projecting in position to prevent the lowering of said plate when the lever is out of engagement with said treadle.

4- The combination with a 'power machine having a tripping treadle, a lever fulcrumed adjacent said treadle and having means for normally holding the treadle in raised inoperative position, guide means for said lever mounted on said machine and having stops for limitin its movement in opposite directions, an a hinged plate mounted to be lowered when said lever is at its extreme limit in one direction whereby said lever is locked in this position, said plate being held against lowering when the lever is moved in t e opposite direction.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

THEODORE BUMANN. Witnesses L. E. WILHITE, DAN W. Mannox. 

